E2E tests validation fixed

[ravinderkumarsap]

Description

Please describe your PR:
What does this PR introduce? :- This pull request (PR) addresses issues outlined in GitHub Issue #206, focusing on enhancing the existing End-to-End (E2E) tests.

• Fixing Requests for Policy Creation:
  Updated the requests for creating policies (Bob_MANAGEMENT_URL and Alice_MANAGEMENT_URL) to include valid Business Partner Number (BPN) values.

• Fixing Requests for Contract Definition Creation:
  Updated the requests for creating Contract Definitions (Bob_MANAGEMENT_URL and Alice_MANAGEMENT_URL) to use valid access policy IDs, contract policy IDs, and asset selectors.

• Enhancements in Get All Policies and Get All Assets:
  Improved response validation for Get All Policies and Get All Assets.
  Updated validation checks to ensure accurate handling of previously created policies and assets.

• Catalog Response Validation:
  Addressed issues in the Catalog Response validation script.
  Validated and updated tests with relative assets for improved accuracy.

• Clean-Up:
  Removed unnecessary Postman collection variables to streamline and declutter the codebase.

Closes #206

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• Copyright and license header are present on all affected files

[paullatzelsperger]

Fine for me. TBH, I haven't checked all Postman RQ/RSes, but assuming they work, this can be merged.

One small thing for the future: Github supports closing keywords, pls use them. I added one to the description now, so issues get auto-closed once the PR Is merged.

[stephanbcbauer]

@hemantxpatel review please :) thx

[hemantxpatel]

There were some cosmetic issues in this PR which are fixed in the PR #255.

@ravinderkumarsap , there's some merge conflict. Please resolve it.